At least four US troops were killed and five others wounded in two separate attacks in Baghdad on Tuesday. In one incident, an American military vehicle exploded near al-Mustansiriyah University in central Baghdad and four soldiers were killed in the burning car. Some witnesses said a rocket-propelled grenade was fired towards the vehicle, Reuters reported.

Another American soldier was injured when a military convoy was fired on with a rocket-propelled grenade near Baghdad airport, the U.S. military said Tuesday morning.

Earlier, at least 10 Iraqis were killed and 15 injured in three explosions in Fallujah, west of Baghdad, including one at the town's main mosques, hospital sources told AFP.

One of the blasts occurred in the Al-Hassan mosque of the town's Al-Askari neighbourhood, with witnesses reporting a ball of fire that ripped through the shrine, destroying two rooms and gouging a hole in its dome.

Among the wounded was Sheikh Laith, the imam of the Al-Hassan mosque whose leg was amputated, they said. According to one report, the blasts came after a US military plane launched several missiles towards the mosque.

Elsewhere, American troops moved in force Monday to arrest the U.S.-appointed mayor of the Shiite town of Najaf, removing him on kidnapping and corruption charges and detaining 62 of his top aides, officials said.

The arrest of the mayor, Abu Haydar Abdul Mun'im, came less than three months after he was installed by American troops after they entered the town in April. The former Iraqi army colonel was unpopular from the start with the local population because of his military background.

In recent weeks, residents of Najaf have demonstrated against Mun'im, accusing him of links to the banned Baath Party. (Albawaba.com)